Which hammer spring for a px4?

I have a Px4 Storm Compact and would like to lighten the DA trigger a bit. (I think its 20lbs right now) I cant seem to find what part I should get. Most sites list things for a 92 or 96 but not the Px4. I think I need a hammer spring to do the job.

I have a compact as well and it has one of the best DA triggers I've shot. I shoot very well with it in DA. My trigger is short, quick, and crisp and light for me. I'd do alot of dry firing w/ snap caps and range work and it should lighten up on it's own just fine.

The 2nd stage of the trigger is great, its the 'long pull' portion I dont like. Its too heavy a pull for my tastes.

Yes, the storm F model is a DA/SA pistol. It is what it is. It is one of the shortest DA pulls on a stock pistol that I'm aware of. I shoot it extremely well, but I've always had DA/SA pistols. Sounds like you may be more suited to a stiker fired pistol like the Walther PPQ. I especially prefer the DA first shot mode for safety reasons, especially when the pistol is carried IWB. Just practice with it and you'll get the hang of it or you may want to opt for a stiker fired pistol. Likewise, if the pistol is brand new I'd wait until i got about 700 rounds, or more through it and see what you think then. I'm not aware of any "D" spring type replacement for the storms as with the 92/96's, but again I don't think it needs it as the storms have a shorter, lighter, quicker, DA pull than the 92's and perhaps all the stock DA/SA pistols out there. If the compact's first DA pull is too long for you, you may have bought the wrong pistol. BTW, a little tip about the first DA pull, line up your sights, keep them lined up and quickly pull the trigger straight back keeping your front sight on target. Don't stage the trigger.

I have a fullsize, and I will say that the DA pull already feels like it has a "D" spring in it. The D pull is lighter than the stock DA pull of a 92FS

Second that one. The PX4's have a nice first DA, most definately shorter and crisper than the un "D" springed 92's. but I shoot very well with the original 92 hammer spring as well. No light primer strikes here, it will literally shoot a pencil across the room and would probably be well suited for small varmint hunting as well.

Staging the trigger generally applies to DA/SA revolvers, DA revolvers and pistols and DA/SA pistols fired in DA mode. In other words you have a somewhat longer trigger pull on the first shot and you stage the trigger somewhat slower in increments until the trigger breaks. Staging the trigger requires a little more cognizance of knowing when the trigger will break and some prefer this. I prefer lining up my sights, keeping them on target and sqeezing the trigger straight back to the rear and bypassing the staging. Once you become proficient w/ the DA and learn to keep your sights on target throughout the trigger pull and a good follow through it'll work for you. I do agree it takes more to master the DA/SA than a good consistent striker fired trigger, but it's arguable both have their advantages.